Soviet Submarine level

[Hamptonsux]

In my case, I had to do something with the transformers. I was a bit ticked off after pouring tons of ammo into the dang things trying to get them to explode, losing several more of my handful of guys to the continued incoming enemy patrols. I finally ...out of desperation, started randomly clicking on them, and out of sheer luck noticed the icon change to the "padlock". Clicked the padlock, which then opened the gate.